Sleep deprivation alters neutrophil functions and levels of Th1-related chemokines and CD4 T cells in the blood.

Purpose: The state of knowledge about the effect of sleep deprivation on the immune system is scarce and conflicting. It would therefore be useful to investigate the consequences of sleep deprivation on the immune system. We have studied the effect of sleep deprivation on the changes in neutrophil functions, and the ex vivo proliferative pattern of CD4 T lymphocytes in relationship with blood cytokine and chemokine levels due to the crucial role of these cells in mounting potent immune responses.

Methods: Healthy volunteers were followed for 3 weeks. They had normal sleep in weeks 1 and 3 and they were sleep-deprived on week 2, sleeping < 6 h per 24 h, a pattern similar to sleep behaviors of many chronically sleep-deprived individuals. We assessed the levels of Th1/Th2 and inflammatory cytokines and chemokines, CD4 T cells, and the NADPH oxidase activation and phagocytic functions in neutrophils.

Results: Our results suggest that sleep deprivation leads to a decreased neutrophil capacity to phagocytose bacteria and activate NADPH oxidase (p < 0.05). Sleep deprivation was associated with a potential increase in CXCL9 levels and decrease in CXCL10/CXCL9 and CCL5/CXCL9 ratios (p < 0.05). Furthermore, our results suggest that the decrease in CD4 T cell due to sleep deprivation was not associated with changes in their proliferation as observed by Ki67 levels, but rather, it correlated with changes in CXCL10/CXCL9 ratio (p < 0.05).

Conclusions: Sleep deprivation may lead to a decreased phagocytosis and NADPH oxidase activity in neutrophils and a decrease in the levels of CD4 T cells which is related to changes in the Th1-related chemokine balance.